Electrical condenser



SePt- 29 1931- w. DUBILIER ELECTRICAL CONDENSER Filed Aug. 4' 1925 Patented Sept. 29, 1931 UNITED STATES PATENT OFFICE WILLIAM DUBILER, OF NEW ROCHELLE, NEW YORK, ASSIGNOB '10 D'UBILIEB CON- DENSEB CORPORATION, OF NEW YORK, N. Y., A CORPORATION F DELAWARE ELECTRICAL CONDENSER -Application le August 4, 1926. Serial No. 127,158.

My invention relates to improvements' in electrical condensers; `specially condensers of a desired capacity which can be obtained with a high degree of accuracy.

An object of my invention is to provide a condenser so made that the ca acity thereof can be adjusted to practically t e exact point required and so designed that it will retain the capacity given to it as long as it is kept in service.

The nature and scope of the invention are set forth in the following description taken with the drawings which show how my invention is employed in practice; and I of course reserve the right to make changes as to shape, size and arrangement of the parts without abandoning the principle of the invention, or exceeding the' scope of the appended claims.

0n the drawings:

Figure l is a View in section of one part of my condenser;

Figure 2 is a longitudinal section of the condenser when the parts are assembled;

Figure 3 is a side view of what is shown in Figure 2, indicating how the condenser can be worked to give the capacity desired;

Figure 4 is a section on the line l-fi of Figure 2;

Figure 5 is a longitudinal section of a comn plete condenser according to my invention;

Figure 6 is the top plan thereof; and

Figure 7 is a rear view thereof, enlarged.

The same numerals identify the same parts throughout.

In making the condenser according to my invention, I may take a section of metal tubing indicated at l, and inside of this section of tubing I insert a plate or sheet of metal such as metal foil 2 both faces of which are covered by insulation, such as sheets of mica 3 to prevent Contact being made between the metal foil 2 and the metal tubing 1. At one end the tubing is then squeezed together as indicated at 4 to grip the mica sheets 3 with the mica foil between them, and the squeezed or flattened section 4 may be erforated as indicated at 5.

When t e condenser is connected in circuit as by joining one terminal of the circuit to the tubing l and the other to foil 2, the tube 1 and the sheet of foil 2 will be of opposite polarity. By inserting the attened end 4 of the condenser between two rollers 6,

I can squeeze the tube l into engagement with the sheets of mica 3 with the metal foil between them to a greater er less extent and thus regulate the capacit For example, as the condenser is placed etween the squeezing rolls 6, the greater the portion of the e0 tube which is compressed and brought closer to the foil 2 between the mica sieets 3, the more will be the capacity given te the condenser. 1vVhen the condenser is made, a piece of tubing and a shet of foil 2 of the e5 required size are selected and then the tube is squeezed between the rollers as much as is required to impart to the condenser the capacity which is needed. The capacity of the condenser is thus set 'and does not ater- 'ze wards vary, and at the same time the desired capacity can be obtained to a very high de grec of'exactness.

For practical use, the condenser is preferably made as shown in Figures 5, 5 and 7, 75 wherein the tube is flattened to some extent throughout its length and compressed at the end 4 against the sheets of mica 3 with the sheet of foil 2 between them to a greater or less extent. Except for the portion 4 u where the tube is squeezed a ainst the mica sheets 3, there will be a smal space between the mica sheets 3 and the inside surfaces of the tube 1, as indicated in Figures 5 and 7, and the greater the portion 4 compressed 85 against the mica sheets 3, the greater will be the capacity of the condenser. The end of the sheet of foil 2 projects beyond the mica sheets 3 and these sheets of mica may terminate within the end of the tube opposite 9o to the compressed end. To strengthen the mechanical construction of the condenser,

I may utilize a pair of plates or pieces of insulation such as a phenolic condensation product 7 placing these plates so that the i6 projecting end of the sheet of foil 2 is between them, and arranging these plates 7 so that they project into the end of the tube l which must be compressed into engagement therewith. For example, the end of the tube may be punched to provide projections 8 which enter recesses in the two pieces ofy insulation 7. The end of the tube thus grips the insulation 7 so that this insulation cannot be withdrawn or displaced, and I can perforate the two pieces of insulation 7 and the portion of sheet of foil 2 between them and pass through this perforation an eyelet rivet 9, and secure this eyelet rivet in place by expanding its ends. Then by passing a conductor through the eyelet rivet 9 which is in contact with the sheet of foil 2, the sheet of foil can be connected to one terminal of an electrical circuit, and the other terminal of the circuit can be connected to the condenser, as by soldering it to the tube l or passingI a conductor through the opening 5 of the crushed end 4. Of course, the opening through the sheet of foil 2, adjacent the opening 5 should be larger than this open ing, so that a conductor passing through the conductor 6 will not make contact with the foil, and the sheet of foil 2 should not be flush with the end of the squeezed portion l but should be terminated well within this end.

This type of condenser is ver easy to make and it gives the capacity desired within very close limits, especially in small condensers where a low capacity is` needed. The end of the tube which receives the insulation 7 can be colnpressed to fit around these pieces very firmly. y

Having described my invention, what I believe to be new and desire to secure and protect by Letters Patent of the United States is 1. An electrical condenser comprising a tubular casing of conductive material forming one electrode, and a sheet of conductive material forming another electrode in said casing and insulated therefrom, the casing being compressed at one end into proximity to the sheet to the required extent and havf ing other portions spaced therefrom.

2. An electrical condenser comprising an electrode formed of a metal casing, a lsheet of conductive material therein, insulating material separating said casing and conductive sheet and comprising the dielectric element of the condenser, said. insulation lying within the casing and said sheet projecting therefrom, and plates of insulationon opposite sides of the projecting part of said sheet y and extending into the end of the casing and secured thereto, said plates and said sheet being perforated, with an eyelet rivet passing therethrough to enable connection to be made with said sheet.

3. A condenser comprising a casing of conductive material forming one armature of the condenser, a sheet of conductive inaterial within said casing forming the other armature of the condenser, dielectric material separating said casing and rconductive WILLIAM DUBILIER. 

